AU2016100565A4 - Tensa DMS advanced motion monitoring system - Google Patents

Abstract

The Tensa DMS is an advanced motion monitoring system that will generally be used for monitoring and recording motion, attitude and position during offshore marine operations. The invention consists of a system that has one or more sensor packages and one or more receiving stations equipped with the Tensa DMS application software. Data can be transmitted from the sensor units to the receiving stations using a cable or by wireless. The invention is portable and can be charged from the PC or it can operate without drawing power from the PC. The Tensa DMS software application uses the motion and position data to calculate and display the crane capacity at the sensor position or a position offset from the sensor. The Tensa DMS software application also calculates and displays the difference in motions, position or attitude between any two points.

Description

BACKGROUND ART

Motion monitoring systems have been in existence for many years. It is now commonplace to have a Motion Reference Unit (MRU) on offshore vessels and rigs. An MRU typically contains accelerometers and gyroscopes and delivers vessel heave, pitch and roil data in a format such as NMEA so that it can be used by other applications.

For offshore lifting it has been understood for a long time that the dynamic loads experienced by cranes are due to the relative velocity between the crane hook and the load as the rigging wire becomes tight. However to determine this it is necessary to be able to measure the velocity of the crane boom tip as well as the velocity of the load which is typically located on another vessel, and to then determine the difference in velocity between the boom tip and the load. Octopus Onboard Is a built-in system that is used for genera! vessel monitoring and records data for a single vessel. Shore Connect also have a built in system that categorizes the deck area of the cargo vessel as green, red, or yellow according to the measured or derived vertical velocity.

SUMMARY OF INVENTION

The Tensa DMS is an advanced motion monitoring system that will generally be used for monitoring and recording motion attitude and position during offshore marine operations. The invention consists of a system that has one or more sensor packages and one or more receiving stations equipped with the Tensa DMS application software.

The sensor package contains 3 orthogonally aligned accelerometers, 3 orthogonally aligned gyroscopes, 3 orthogonally aligned magnetometers and a Global Positioning System (GPS). The sensor package may additionally have a battery and power conditioning circuitry and may additionally have a wireless transmitter and receiver. The sensor package has a Universal Serial Bus (USB) connection that allows power to be transmitted to the sensor package and which also allows data to be transmitted to the receiving station.

The receiving station consists of a Microsoft Windows based computer running the Tensa DMS application software. The receiving station may communicate with the sensors by USB cable or by wireless.

TECHNICAL PROBLEM

There are a number of technical problems that the Tensa DMS overcomes. a) Some of the existing products require fixed installation into a specific vessel as the data is highly tailored to the layout and dimensions of the dedicated vessel. b) The existing products do not provide real time information on the crane’s lifting capacity at the current load position. The cargo transport vessel is not stationery and will approach the facility with the crane until the crane has sufficient capacity at the radius of the load to lift the load.

Existing equipment does not dynamically update the crane capacity at the current load position according to both its distance from the crane and the motions of the load. c) Some current products are designed specifically for lifting. There are applications where the distance and relative motions between a point on one facility and another point on a second facility need to be known. This Information is not readily determined from other systems,

SOLUTION TO PROBLEM in relation to the technical problems a), b) and c) defined above, the Tensa DMS provides the solution as described below: a) The Tensa DMS is battery powered and portable although it can be powered from a fixed power supply and built in. Data is calculated for the specific point of Interest which is typically where the heavy load to be lifted is placed on the deck of the transport vessel. A single unit can be shared by multipie vessels that access a facility. b) The Tensa DMS reads the GPS position of the load and determines the distance from the crane centre of rotation. When the crane is on a fixed installation, the location of the crane is input as a fixed point and the distance Is then calculated using the Northing and Easting offsets determined from the Universal Transverse Mercator (UTM) coordinates of the 2 points.

Conversion from degrees, minutes and seconds to UTM is built Into the Tensa DMS software application. When the crane is on a floating or moveable facility, the crane position can be logged in real time using the Giobai Positioning System (GPS) in a second Tensa DMS unit. The distance between the crane and the load is then calculated as for a fixed facility with a fixed crane. c) The Tensa DMS hardware and software is designed to support the receipt and processing of data from many sensors simuitaneousiy. The DMS application can create a differential data stream from heave acceleration, heave velocity, heave, pitch, roll, heading, position, velocity and acceleration. In applications where the distance and relative motion between two points is required, a data stream of this differential data can be easily selected. This has applications where it is necessary to monitor the two ends of a gangway connecting two facilities and the distance between the facilities must remain within a specified range and the relative motions between the two ends must not exceed the gangway operational limits.

ADVANTAGEOUS EFFECTS OF INVENTION

Whilst there have been devices designed to specifically address some particular applications for specific vessels and operations, the Tensa DMS method of receiving and processing the data allows it to be implemented very quickly and easily, in particular if there are one-off heavy lifts that need to be performed, the mobility and method of displaying data applicable to a single point rather than for a specific vessel means that there is no customisation required before using it.

By using the Tensa DMS for one-off heavy lifts offshore, the operations can be undertaken more safely because there is a greatly reduced chance of overloading the crane. The operations can most likely be done more economically because the limiting conditions for a lift are able to be quantified and safety margins currently needed to account for the inaccuracy of estimation of the load velocity can be reduced.

DESCRIPTION OF EMBODIMENTS

The invention may be better understood with reference to Figure 1 which is an illustration of embodiments of the invention in which: (Item 1) is the sensor unit which contains the accelerometers, gyroscopes, magnetometers and their peripheral eiectronics and which may also contain a battery, power conditioning circuitry, a wireless receiver and wireless transmitter. The wireless antenna (item 4) may be attached to the sensor enclosure externally as shown or may be internal.

The sensor unit (item 1) may be connected to a local receiving station (item 2) by a USB cable (Item 3) or it may be connected to a remote receiving station (item 5) by wireless. When connected by wireless, the wireless signal from the sensor unit (item 1) is received by the wireless module (Item 6) and communicated to the receiving station by cabie which may be a USB cable or a serial cabie. The local and remote receiving stations both run the Tensa DMS application software.

Claims (5)

1. A stand alone motion sensor and associated software package where the motion sensor may be powered entirely by USB or powered by a battery which can also be recharged using a USB2 power source using a USB cable which has an optional power switch so that the heave motion sensor can be run from low power tablet and notebook computers without draining the battery of the low power tablet or notebook.

2. A motion sensor and software package according to claim 1 where the computer software program for receiving, displaying and logging motion data uses the measured vertical heave velocity of the load to be lifted to select or derive using interpolation the appropriate crane load chart from a library of crane charts relating to different environmental conditions for an offshore crane.

3. A motion sensor and software package according to claim 1 where the computer software program for receiving, displaying and logging motion data uses the measured distance between the position of the load sensor on one vessel from which the load is to be lifted or the derived position of the load on this vessel and the positon of the crane centre of rotation on another vessel of fixed structure to determine the crane capacity at the current load position.

4. A motion sensor and software package according to claim 1 where the computer software program can receive data from one or two sensors in real time to calculate the difference between a single set of sensor data and a fixed point in space or between two sets of sensor data to create a set of parameters that are then treated as sensor parameters in their own right where this data known as a differential data set can be used for determining the distance between the two sensors or between one sensor and a fixed point.

5. A motion sensor and software package according to claim 1 that can additionally be in the form factor of a floating buoy which can also have an easily removed keel and which when floating is used to determine the motion of the water surface and which can also be used on a desktop to determine the motions of a floating vessel.